This invention relates to an improved reversing valve construction and parts therefor as well as to methods for making such a reversing valve construction and the parts therefor.
2. Prior Art Statement
It is well known that reversing valve constructions for heat pump systems and the like have been provided wherein each includes a housing means carrying a movable piston-like valve member that controls port means of a valve seat means of the housing means through the relative position of cavity of the valve member relative to the port means.
For example, see the following four U.S. patents:
U.S. Pat. No. 3,032,312--Greenawalt PA0 U.S. Pat. No. 3,056,574--Greenawalt PA0 U.S. Pat. No. 3,357,453--Mingrone et al PA0 U.S. Pat. No. 3,985,154--Hargraves
Each reversing valve construction of the above four patents appears to have a rigid and non-flexible valve member disposed in sliding contact with its cooperating valve seat surface, the first three above patents each having the valve seat means thereof formed by a separate part disposed and secured in the housing means and being provided with a flat surface against which a flat surface of the movable valve member engages and slides in sealing relation therewith whereas the above patent to Hargraves has the valve seat means formed from a non-formed part of a cylindrical tubular housing member so as to be provided with an arcuate surface against which an arcuate surface of the valve member slides in sealing relation therewith.
Actual production devices that appear similar to the above four patents were examined and those similar to Mingrone et al and Hargraves were found to have rigid metallic surfaces of the valve members to be disposed in sliding relation with respective metallic surfaces of the valve seat means, the device similar to the patent to Greenawalt, U.S. Pat. No. 3,032,312 was found to have a non-flexible and rigid plastic annular part forming the sliding surface of the valve member and being captured at its inner and outer peripheries by metallic retainers of the valve member whereby the entire valve member is rigid, and the device similar to the patent to Greenawalt, U.S. Pat. No. 3,056,574 was found to have the entire valve member formed of plastic material and of such a thickness that the same is not flexible.
It is also known to provide an outwardly biased annular sealing member around a cavity in a valve member to seal the same to a valve seat means.
For example, see the following U.S. Pat. No. 3,349,800--Herion et al.
It appears that the annular sealing member of the above patent to Herion et al always surrounds a single port in the valve seat means to always interconnect that single port to the cavity of the valve member.
It is also known to outwardly bias a valve sealing member with a resilient O-ring like member disposed between the valve member and the valve sealing member.
For example, see the following U.S. Pat. No. 3,642,248--Benware.
It appears that the sealing member of the above patent to Benware is disposed in an annular recess of a valve member and is urged outwardly from that recess to seal against a valve seat means by a resilient O-ring member also disposed in the recess between the valve member and the sealing member.